Translucent medium for use in photographic arts



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FIREDERIGK W. HQCHSTETTER, 0F DAYTON, OHIO, ASSIGNOR OE ONE-HALF T0 I.

@HMER, OF DAYTON, OHIO.

TRANSLUCIENT MEDIUM FQR USE IN PHOTOGRAPHIC ARTS.-

No Drawing. Original application May 21, 1921.

T 0 all whom it may concern:

Be it-known that I, FREDERICK W. Hocrr- STETTER, a citizen of the UnitedStates, residing at Dayton, in the county of Montgomery and State ofOhio, have invented certain new and useful Improvements in Translu centMediums for Use in Photographic Arts, of which the following is aspecification.

The principal object of my invention is to provide a translucent mediumfor use in the photographic arts in the place of nitro cellulosecompounds now generally used. By nitro cellulose compounds I refer tothe various translucent and transparent substances used in photographicand similar arts. many forms of which are termed films.

It is the further object of my invention to provide a medium oftranslucent character which can be used not only for negatives but alsofor transparencies and diapositives.

The range of usefulness of my invention isonly limited so far as thephotographic art is concerned,'by the limits of the art itself. It isapplicable to film purposes for both still photography and movingpictures.

It is one of the signal objects of my invention, that the translucentmedium becomes an integral portion of the photographic negative or otheruse to which it may be put, as distinguished from the attempts in thepast to use translucent medium on supports which were merely temporaryand had to be removed from the remainder of the negative or positivebefore the operation could be complete. My object is to provide aermanent base of translucent character like the ordinaryfilm, whichshall be entirely fireproof and not inflammable. This is a very materialadvantage over the present film with its highly inflammable andexplosive character incurring great danger in handling. shipping anduse, as Well as in the course of manufacture.

It is my object to provide, as has not hitherto been provided, atranslucent medium which shows no grain whatsoever and is free from anyopacity which might detract from the usefulness and beauty of theresulting images, projections or positives.

Furthermore, I have succeeded in thus making such an advance in the artthat the result is not only translucent, without grain and notinflammable, but also I have been able to use the ordinary materialfound on Specification of Letters Patent. Patented June 13, 1922.

filed November 10, 1919, Serial No. 336,898. This application filedSerial No. 471,524.

the market, such as paper of varyingcharao ters, of varying methods ofmanufacture, of varying lengths of fiber or lengths of material whichcompose the paper and make up its structure. In accomplishing theseseveral'objects, I have not affected the rapidity with which positivesmay be made from the negatives, nor efiected the question of projectionof images from film in moving pictures where the film is made up of mytranslucent material.

A further object of my invention is to so provide such translucentmedium that no unpleasant-refraction would be encountered in the case ofprojection of moving pictures due to any refractive properties whichmight either be left in-my translucent medium or created by my processof producing it.

I transform my paper thatI use for this purpose, which may be of anykind, although I have some preferences which will be stated later, inthe following way: I select a drying oil, such as linseed oil. 10 oz. ofthis oil is heated to 100 degrees F. I then use a substance to give ahard smooth surface to the paper to which dust will not cling. One ofthe preferred substances is bleached shellac, of which I use 3 oz. Ithen select a dehydrating agent such as alcohol, of which I use 20 oz.in this combination. It also acts as a solvent for the shellac and acarrier of it to further the combination of it with other elements ofthe compound and article.

The substances mentioned above are mixed at 100 degrees F. in the ordergiven successively, although the mixing of the ingredlents in anyparticular order is not essential to my invention, but preferable.

The mixture is now ready for application to the paper in the papersfinishedv state.

The finished paper is heated to about 100 degrees F. by any suitablemeans, although I prefer a series of hot rollers of the propertemperature over which the paper is passed to give it a suitabletemperature, but care must be used not to heat the paper to such atemperature as to injure its color. I prefer to use white paper,although that is not essentlal. The paper thus heated is then passedthrough the solution, the formula for is returned to its normaltemperature, thus allowing the paper to dry. The paper becomestranslucent as soon as the solution thoroughly permeates it.

In order to protect the translucency of the paper and toprevent it frombeing injured, T coat the paper with another substance after it has beentreated to make it translucent. This compound, with which it is treated,is as follows: ll take 15 grams of hard gelatin, melted by heat, and mixit with 1 oz. of linseed oil and an alcoholic solution of chrome alum. Iprefer to use, however, a mixture for this purpose of hard gelatin,melted by heat and bichromate of potash without oil. Either of thesecompounds will treat the paper to preserve its translucency, actlike amordant and act to prevent the formation of an alkali and to prevent theemulsion from frilling or peeling off from the translucent paper whenthe sensitizing emulsion is applied. The sensitizing emulsion may beapplied either before or after the paper has been made translucent.

I do not desire to confine myself to the particular components of thecompounds that I have enumerated above, because equivalent ingredientsmay be used if they have the properties for the purposes intended. Thetemperature that l have stated is a preferred temperature, but it shouldbe understood it is not essential that this temperature be exact.

In case the paper is treated without being heated, in a cold solution,then the solution will be composed of the following; A drying oil, suchas linseed oil and a dehydrating agent, such as absolute alcohol. Theshellac is omitted. ll do not prefer this form.

In case it is desired to make the paper translucent during the course ofits original manufacture before it is completed, it is possible toreadily do this by passing the paper, after it has sufficiently set, butis still in its plastic .state, through (the solutions mentioned,depending upon whether or not it is desired to treat the paper at itsnormal temperature or above its normal temperature.

One of the preferred forms of a medium for treatment to make ittranslucent is a paper composed of short fiber cotton made up from rags.Ordinarily, it has been thought that the shorter the fiber, the greaterthe refraction of light, due to the multiplicity of surfaces within thepaper. I find, however, in my invention that the length of the fiber isnot of great moment,

although the short fibers are preferable.

The use of short fiberswill make even more perfect the perfection of mytranslucency.

If it is desired to treat the paper while in its plastic state with theheated solution, it is passed into the heated solution first mentionedand then passed over heated rollers or conveyors into the secondsolution and then gradually cooled.

If it is desired to treat it while in its plastic state with the coldsolution, the heating arrangements are omitted.

Tn the foregoing, T have mentioned paper and paper pulp as a medium tobe treated. Tn the following claims, I have also mentioned paper andpaper pulp. In doing so, I have merely used these terms for the purposesof illustration and suggestion, but I do not desire to be confined tothis medium alone for making opaque substances translucent.

This application is a division of Hochst-etter application Serial No.336,898.

Having thus fully described my invention, what I claim as new and.desire to secure by Letters Patent, is: 1

1. A compositon of matter for treating paper to render the sametranslucent comprising a drying oil, a glazing medium and a dehydratingagent only.

2. In combination, linseed oil, bleached shellac and absolute alcohol.

3..A composition of matter for treating paper to render the sametranslucent comprising linseed oil, a glazing medium, and a dehydratingagent only. a

4. A composition of matter for treating paper to render the sametranslucent comprising a drying oil, bleached shellac, and a dehydratingagent only.

5. A composition of matter for treating paper to render the sametranslucent comprising a drying oil, a glazing medium, and absolutealcohol only.

6. A composition of matter for treating paper to render the sametranslucent comprising a drying oil, bleached shellac, and absolutealcohol only.

7. In combination, 10 oz. of linseed oil, 3 oz. of bleached shellac and20 oz. of absolute alcohol.

8. lln combination, a drying oil, adehydrating agent and paper.

In testimony whereof, I aflix my signature.

FREDERICK W. HOCHSTETTER.

